Running the OpenCPN Flatpak beta requires a working Flatpak installation. See https://flatpak.org/setup/ for platform-specific installation procedures.
Running the beta is done from the command line. It is installed using
$ flatpak install flatpak install https://flathub.org/beta-repo/appstream/org.opencpn.OpenCPN.flatpakref
Once installed, the beta version will be the default alternative and the one started when clicking on the OpenCPN desktop icon. However, if an earlier version was installed before the beta it is still available and can be started using
$ flatpak run org.opencpn.OpenCPN/stable
To start the beta from the command line:
$ flatpak run org.opencpn.OpenCPNbeta
To update the beta to latest version:
$ flatpak update org.opencpn.OpenCPN/beta